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101.
Calixpyrroles, as new macrocyclic receptors, have gain increasing interest in host-guest chemistry. Pioneering work in this area by Sessler and co-workers have evidenced that calix[4]pyrroles are effective anion binding agents and have used for anion binding, sensing and new anion separation technologies1, 2. In this letter, we report that calix[4]pyrroles A, B and C3,4 (Scheme 1) can serve as additives in CZE for the separa- tion of halide ions. Scheme 1 A B C When analyzing anions with…  相似文献   
102.
Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2…  相似文献   
103.
Interactions of DNA with various molecules are interesting because of its importance in gene expression process of living cells. Several models for the interaction between DNA and some small molecules have been proposed1-4. We are interested in the possibility of the interaction between DNA/RNA and neurotransmitters, such as dopamine and epinephrine, because these species are very important substances for keeping normal physiological functions of brain and neuro system. However, no report…  相似文献   
104.
Baker''''s Yeast Mediated Reduction of Optically Active Diketone   总被引:1,自引:0,他引:1  
Baker's yeast (BY) mediated reduction of synthetic substrate is a useful method for preparing chiral intermediate in synthesis chemistry1,2, because it is readily available and inexpensive. The selectivity is generally predicted by Prelog rule3, that is, a hydride is transferred to the re face of the prochiral ketone.The baker's yeast mediated reduction of bicyclic diketones was previously reported by several groups4-6, but to our knowledge, no application of this reduction to sesquiter-pene-…  相似文献   
105.
In recent years, many efforts were focused on the preparation and characterization of phosphazene which contained a framework of alternating phosphorous and nitrogen atoms with two substituent groups attached to each phosphorous atom1. It is noticeable that cyclophosphazene, especially hexaaryloxyphosphazene and perfluoroaryloxyphosphazene exhibit excellent thermal and chemical stability which can be used as fireproof materials, high temperature lubricants, vacuum pump oils and hard disk surfac…  相似文献   
106.
The drug overdose and addiction is a serious international problem. Therefore developing a rapid, accurate, convenient and cheap method for detecting morphine in urea is useful and necessary, especially for investigation of epidemiology, identification of medical jurisprudence and determination of drug addict etc. There are many compounds that are similar to morphine in chemical structure and tend to have cross-reaction with the anti-morphine antibody. In order to reduce the cross reaction a…  相似文献   
107.
Preparing Nano-ZnS by Solid State Reaction at Room Temperature   总被引:3,自引:0,他引:3  
Solid-state reaction has been studied for a long time1-3. In recent years, some researches have been focused on the preparation of coordination compounds at low temperatures or even at room temperature4-5. In this letter, preparation of ZnS nanoparticles by using solid state reaction at room temperature is reported.ZnS nanoparticles were prepared as follows: Zn(CH3COO)2 and Na2S?9H2O, in equal molar ratio, were ground in agate mortar. After 20 minutes, the powder was washed by water and …  相似文献   
108.
Chrysotricine 1 was isolated from the Chinese herb medicine Hedyotis Chrysotricha and was shown to possess antitumor activity1. Its structure has been elucidated as a novel zwitterionic (-carboline alkaloid containing a 2,2,5-trisubstituted tetrahydrofuranyl group. The (-carboline compounds have attracted considerable attraction in recent years because of their promising and intriguing biological activities2. Recently, we have established the absolute configuration of chrysotricine by the fir…  相似文献   
109.
New diterpenoid glucosides from Siegesbeckia pubescens   总被引:5,自引:0,他引:5  
Plants of the genus Siegesbeckia are annual herbs widely distributed in tropical and temperate zones and they are used as a traditional medicine to treat rheumatic arthritis, hypertension, malaria, neurasthenia and snake-bite in China. In previous papers, we reported on five new ent-kaurane and ent-pimarane diterpenoids, siegesbeckioside, siegesbeckiol and siegesbeckic acid1, orientalin A and B, and eight know compounds2,3. The present paper describes the isolation and structural elucidation …  相似文献   
110.
三种蒙药中微量元素含量与疗效相关性分析   总被引:2,自引:0,他引:2  
用原子吸收分光光度计测定了蒙药扎木萨-4,阿拉坦-5,阿那日-5中多种微量元素及常量元素的含量。结果表明,这三种健胃消食蒙药中Mg、Fe、Mn、Zn均较高,呈一定相关性,而有害元素Pb、Cd很少,探讨了三种蒙药中微量元素与其疗效的关系。  相似文献   
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